CAJ | 학술논문

目的利用三维有限元方法探讨J钩高位牵引辅助压低并内收上颌前牙的生物力学机制,以期为临床治疗提供参考.方法在ANSYS 14.0软件中建立包括上颌牙列、牙周膜、直丝弓矫治器及上颌骨的三维有限元模型.模拟J钩施加1.5 N力量压低内收上前牙,A组加载于侧切牙近中,B组加载于侧切牙远中.牵引方向与矢状面保持30°不变、与(牙合)平面的角度在20°～ 60°之间,每间隔5°设置1种工况,两组共18种工况.分析上前牙位移及牙周膜应力情况.结果随着牵引角度增大,上前牙位移趋势逐渐由舌向移动为主伴压低的顺时针旋转移动,变为整体压低、内收移动,最后变为压低伴唇向倾斜的逆时针旋转移动.在侧切牙近中以35°加载或在侧切牙远中以45°加载时,上前牙出现相对均匀一致的整体压低、内收移动,整体无旋转的趋势.结论对于唇倾度正常的上颌前牙,J钩高位牵引加载于侧切牙近中更有利于前牙的整体压低和内收,临床上应根据个体情况和治疗目标调整牵引角度.
목적 이용삼유유한원방법탐토J구고위견인보조압저병내수상합전아적생물역학궤제,이기위림상치료제공삼고.방법 재ANSYS 14.0연건중건립포괄상합아렬、아주막、직사궁교치기급상합골적삼유유한원모형.모의J구시가1.5 N역량압저내수상전아,A조가재우측절아근중,B조가재우측절아원중.견인방향여시상면보지30°불변、여(아합)평면적각도재20°～ 60°지간,매간격5°설치1충공황,량조공18충공황.분석상전아위이급아주막응력정황.결과 수착견인각도증대,상전아위이추세축점유설향이동위주반압저적순시침선전이동,변위정체압저、내수이동,최후변위압저반진향경사적역시침선전이동.재측절아근중이35°가재혹재측절아원중이45°가재시,상전아출현상대균균일치적정체압저、내수이동,정체무선전적추세.결론 대우진경도정상적상합전아,J구고위견인가재우측절아근중경유리우전아적정체압저화내수,림상상응근거개체정황화치료목표조정견인각도.
Objective To investigate the biomechanics of J-hook headgear in En mass intrusion and retraction of maxillary anterior teeth and provide guidance for clinical treatment.Methods A three-dimensional finite element model of maxillary teeth,periodontium,straight wire appliance and maxillary bone was established in ANSYS 14.0.En mass retraction of anterior teeth with force of 1.5 N through J-hook headgear was stimulated.Force was applied mesial to lateral incisor in group A and distal to lateral incisor in group B.The force direction was 30° to the sagittal plane and 20° to 60° to the occlusal plane.Force direction to the occlusal plane was changed every 5°and 18 cases were calculated.Displacement of upper anterior teeth and stress distribution in the periodontium were analyzed.Results As the degrees of force direction to the occlusal plane increased,the moving pattern of upper anterior teeth changed from clockwise rotation(lingual movement with intrusion) to bodily retraction and intrusion,and counter-clockwise rotation (intrusion with labial movement).With the force direction of 35° to occlusal plane applied mesial to lateral incisor or force direction of 45° to the occlusal plane applied distal to lateral incisor,bodily movement of upper anterior teeth without rotation was achieved.Conclusions Placement of J-hook mesial to lateral incisor enable orthodontists to maintain better en mass intrusion and retraction of upper anterior teeth.The direction of J-hook should be adjusted according to individual condition and treatment objective.